In area 0 I have two loopbacks: and (both /24's).

I'm trying to configure a summary to roll the two up. Given the rest of the topology, I'm using area X range command.

This is my input and the console's output. What am I missing?

ZEUS(config-router)#area 0 range
% OSPF: Inconsistent address/mask for area range

Wouldn't this summarize from up to

  • It might be useful to post relevant bits of the configurations as well as the platform/software version(s). Dec 12, 2013 at 20:34

2 Answers 2


All loopbacks in OSPF are advertised with a mask by default (see "LOOPBACK" network type), regardless of what you've configured the netmask as on the interface. If you want to announce your loopbacks with anything that's not a /32 you need to configure them as point-to-point (ip ospf network point-to-point under the Loopback interface configuration).

EDIT: Since you've stated you've already done this, my next observation is that you've given the wrong network address for the area range command. If you want to announce the summary you'd need to announce it with the network address, ie area 0 range

Also be aware that any traffic to or will be blackholed.

EDIT #2: @Christian's answer is also correct if you wanted to summarize just those two /24's into a /23: area 0 range

  • I've already done that, lets stay on topic, I'm asking why do I get the inconsistent address/mask feedback, when I know for a fact that the range of includes both loopbacks?
    – A L
    Dec 12, 2013 at 20:39
  • 1
    See my updated answer. Dec 12, 2013 at 20:49
  • 2
    I figured it out: wrong subnetting! Gragh, need to practice more. It's inconsistent because .2 is half way through a block of 4 /24's, I moved it up to to test this and it worked. Doing also worked to summarize the two loopbacks I had. Thanks for all of your help, and enduring my ignorance!
    – A L
    Dec 12, 2013 at 21:26
  • A,L you wanted 2.0 thru 3.255. If you still want this range specifically simply change it to /23. See my answer Dec 12, 2013 at 22:21
  • He already noted that in his comment above yours... Dec 12, 2013 at 22:24
3 =

If you want .2.0 thru .3.255 specifically you'll need =

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